Rolling of flat strips



D. A. EBERHARDT ROLLING OF FLAT STRIPS Filed Aug. 2, 1940 Patented Feb. 9, 1943 UNITED STATES PATENT OFFICE noume or run s'rmrs Daniel A. Eberhardt, St. Louis, Mo. Application August a, 1940, Serial No. 349,409

4 Claims.

This invention relates to a method of forming flattened strips from a galvanized rod or wire.

An object of the invention is to provide a method of forming flat strips from galvanized rod or wire so as to avoid cracking the zinc coating.v

There are several advantages in the invention, one of which is economy. Galvanized rod or wire may be obtained commercially, and then rolled by the present process to produce a rustproofed flat strip at a large saving, over the cost duced economically by ordinary hot dipped galvanizing. In the-hot dip process of galvanizing, the temper of the steel and its hardness is reduced, while rolling by the present process raises the temper andincreases the hardness.

Further advantages may be inherent in the process, and may be apparent from the following detailed description.

The drawing is an elevation showing apparatus which may be used in practicing the process in this invention.

The apparatus consists essentially of a pair of opposed rolls i and 2, which are driven simultaneously by a motor 3. The rolls have opposed surfaces, by which the blank may be shaped to form the flat strips. These surfaces may be such as to form, two sides on the strips which are parallel, or the rolled surfaces may be such as to form other shapes.

As a rod or wire or blank B is fed to the rolls I and 2 it is wetted by a lubricant, such as turpentine. This wetting agent is contained in a trough 4, into which dips a wheel or grooved pulley 5 to elevate by capillary attraction a sumcient quantity of the lubricant to wet the blank pulley I2 on the shaft of which is keyed a pinion l3, meshing with a gear ll keyed to the shaft of the roll 2.

The rolls l and 2 are power connected by Sears [5.

The wetting wheel 5 is driven by the gear I meshing with and driving a pinion I5 keyed to a both in front of and behind the pressure rolls may be employed.

It is known, of course, that it is common practice to roll fiat metal shapes from round bar or stock, but it has heretofore been assumed that it was impossible to roll galvanized or zinc coated wire, because of the tendency of the coating to crack. In practicing the present invention, however, advantage has been taken of the peculiar properties of 21x c, so that in rolling the zinc does not crack. Zinc when cold is brittle, is malleable at 120 150 C. (250300 F.), and is very brittle at 200 C. It has been found that by rolling the stock at a speed sufficient to heat the stock at the rolls by the action of the rolls to a temperature at which the zinc is malleable, satisfactory results are obtained. This temperature B as it passes to the rolls. This wetting is f'aciiiplement the heat obtained from the action of the rollers by applying heat or it is possible to cool the work in order to maintain the proper temperatures.

It has been found in practice that satisfactory results are obtained, provided the stock is not deformed beyond certain limits so that the elongation of the zinc coating does not substantially exceed 25% in any direction. Or, more particularly, the best results are obtained while deforming the stock in such a manner that the longitudinal elongation of the zinc coating is substantially uniform with its lateral elongation, and this longitudinal elongation should not be in excess of 25%. The longitudinal elongation with respect to the lateral elongation can be controlled by increasing or decreasing the size of the rollers. Other factors being equal, the larger the rolls the less longitudinal elongation will be secured and vice versa.

A difliculty or a problem presented by the rolling of the galvanized stock at the temperature indicated, has been overcome or solved by the use of a'wetting agent or lubricant. If the galvanized stock is passed through the mile. at the temparature indicated while dry, particles of the zinc coating will adhere to the rolls, and will soon cause diillculty. This is avoided by wetting this stock with a proper agent as it is about to be placed between the rolls. Many satisfactory wetting agents or lubricants have been found, among them some are turpentine, kerosine, gasoline and vinegar. Such a. wetting agent should be such as not to oxidize or discolor or spot the surface; it should be volatile, so that it will be expelled from the article by the heat imparted by rolling to avoid the necessity of cleaning the strips. It should also be safe so as to avoid damage of fire or injury to the operator. Of the wetting agents, which have been mentioned, turpentine has been found to fulfill the requirements. It is cheap enough for economical use; it presents no hazards; it evaporates completely from the strips without any special attention; it

operates sufllciently as a lubricant; and it does not oxidize, discolor or spot the product. It is not doubted, however, that other wetting agents quite as satisfactory may be found and utilized.

By way of example to illustrate the invention, and not by way of limitation, a typical operation may be described. The stock selected is IO-gage soft galvanized merchants or fence wire, which is well known commercially. This stock has a temper equivalent to that of No. 4 or No. 5 cold rolled steel. This wire is passed between 5". rolls after it has been wetted with turpentine. The rolls are so formed as to produce a flat cross section approximately 1%" x H, and the rolls are driven at a speed to pass the stock at the rate of approximately 240 ft. per minute.

It has been found'that this operation produces a satisfactory product with a longitudinal elongation of approximately The lateral elongation of the surface coating is approximately the same. The size of th rolls and the speed of pass must, of course, be different for stock and shapes of different sizes. It has been found that the surface coating of zinc is not damaged by claims, parts of the invention may be used without the whole, and various improvements and steps may be added thereto.

I claim:

1. The method of forming flattened strips comprising passing a galvanized rod between pressure rolls at a pressure sufficient to substantially deform the rod and at a speed sufficient to heat the rod at the rolls by the action of the rolls from room temperature to a temperature between 250 and 300 F.

2. The method of forming flattened strips comprising passing a galvanized rod between pressure rolls at a pressure sufllcient to substantially deform the rod while maintaining a temperature between 250 and 300 F. in the rod at the rolls.

3. The method of forming flattened strips comprising passing galvanized rod having a zinc coating between pressure rolls at a pressure sufllclent to substantially deform the rod while maintaining such a temperatur in the rod at the rolls at which the zinc is malleable and will not crack under the deformation caused by the rolls.

4. The method of forming flattened strips comprising passing a galvanized rod having a zinc coating between pressure rolls at a pressure sufllcient to substantially deform the rod while maintaining a temperature in the red at the rolls at which the zinc is malleable and will not crack under the deformation caused by the rolls, and while limiting the change in form of the rod so that the elongation of the zinc coating does not substantially exceed 25% in any direction.

DANIEL A. EBERHARDT. 

